1. Field of the Invention
This invention relates generally to adsorbent particles that have improved adsorbent properties and/or improved or newly existing catalytic properties, including room temperature catalytic capability.
2. Background Art
Oxides of metals and certain non-metals are known to be useful for removing contaminants from a gas or liquid stream by adsorption mechanisms. For example, the use of activated alumina is considered to be an economical method for treating water for the removal of a variety of pollutants, gasses, and some liquids. Its highly porous structure allows for preferential adsorption capacity for moisture and contaminants contained in gasses and some liquids. It is useful as a desiccant for gasses and vapors in the petroleum industry, and has also been used as a catalyst or catalyst-carrier in air and in water purification. Removal of contaminants such as phosphates by activated alumina are known in the art. See, for example, Yee, W., "Selective Removal of Mixed Phosphates by Activated Alumina," J. Amer. Waterworks Assoc., Vol. 58, pp. 239-247 (1966).
U.S. Pat. No. 5,242,879 to Abe et al. discloses that activated carbon materials, which have been subjected to carbonization and activation treatments, and then further subjected to an acid treatment and a heat treatment in an atmosphere comprising an inert gas or a reducing gas, have a high catalytic activity and are suitable as catalysts for the decomposition of hydrogen peroxide, hydrazines or other water pollutants such as organic acids, quaternary ammonium-salts, and sulfur-containing compounds. Acid is used to remove impurities and not to enhance the adsorbent features.
Ion implantation has been used in integrated circuit fabrication. U.S. Pat. No. 4,843,034 to Herndon et al. discloses methods and systems for fabricating interlayer conductive paths in integrated circuits by implanting ions into selected regions of normally insulative layers to change the composition and/or structure of the insulation in the selected regions. It is stated that a wide range of insulative materials can be rendered selectively conductive, including polymeric insulators and inorganic insulators, such as metal or semi-conductor oxides, nitrides or carbides. Insulators which can be processed according to this patent include silicone dioxide, silicon nitride, silicon carbide, aluminum oxides, and others. It is disclosed that implanted ions can include ions of silicon, germanium, carbon, boron, arsenic, phosphorous, titanium, molybdenum, aluminum, and gold. Typically, the implantation energy varies from about 10 to about 500 KeV. It is disclosed that the ion implantation step changes the composition and structure of the insulative layer and is believed also to have the effect of displacing oxygen, nitrogen, or carbon so as to promote the migration and alloying of metal from the conductive layer(s) into the implanted region during the sintering step. The implantation also is believed to have the physical effect of disrupting the crystal lattice, which may also facilitate the fusion of the metal. This results in a composite material in the implantation region essentially consisting of the disruptive (disrupted) insulator and implanted ions. In the working examples, ions of silicon were implanted into the particular region of the silicon dioxide layer using a direct implantation machine.
U.S. Pat. No. 5,218,179 to Matossian et al. discloses a plasma source arrangement for providing ions for implantation into an object. A large scale object which is to be implanted with ions is enclosed in a container. The plasma is generated in a chamber which is separate from, and opens into the container for a plasma source ion implantation working volume. The plasma diffuses from the chamber into the container to surround the object with substantially improved density compared to conventional practice. High voltage negative pulses are applied to the object, causing the ions to be accelerated from the plasma toward and be implanted into the object.
Thus, there has been a need in the art for adsorbents that have improved ability to adsorb particular materials, especially contaminants from a gas or liquid stream, to thereby purify the stream. Also, there has been a need in the art for catalysts that have the ability or that have an improved ability to catalyze the reaction of contaminants into non-hazardous products.
Additionally, there has been a need in the art for adequately agglomerating adsorbent particles together to form a composite particle for performing simultaneous multiple adsorptions and purifications. Prior art particles typically mask at least some of the adsorbent or catalytic sites on the particles, thus reducing the efficiency or performance of the particles.
In the present invention, none of the above-cited documents discloses compounds, compositions or processes such as those described and claimed herein.